Bielastic fabric and its manufacturing process

ABSTRACT

There are described a bielastic fabric comprising biopolyamide yarn and elastane yarn, having excellent elastic properties and high dimensional stability, and a cost-effective, efficient process for obtaining it.

TECHNICAL FIELD

The present invention relates to a bielastic fabric comprisingbiopolyamide yarn and elastane yarn, having excellent elastic propertiesand high dimensional stability, as well as to a cost-effective,efficient process for obtaining it.

BACKGROUND OF THE RELATED ART

Environmental impact issues related to the textile industry, inparticular water and air emissions, use of water and energy, are knownand of current interest.

It is therefore an important goal to be able to produce textiles andclothing products which reduce energy consumption and environmentalimpact, without impairing the technical features of the productsthemselves.

It is thus an object of the present invention to provide a solution tosuch problems, which simultaneously allows excellent qualities andtechnical performance to be obtained.

SUMMARY OF THE INVENTION

Said object is achieved by a bioelastic fabric as claimed in claim 1.

In another aspect, the present invention relates to a process forobtaining such a bielastic fabric.

In a further aspect, the present invention relates to a clothing orfurniture item, at least partially made of such a bielastic fabric.

DESCRIPTION OF THE DRAWINGS

The features and advantages of the present invention will become moreapparent from the following detailed description, from the embodimentsshown by way of non-limiting examples, and from the accompanyingdrawings, in which:

FIG. 1 shows the pattern of jersey fabric (weave of stocking stitch)seen from the knit side on the left and from the purl side on the right;

FIG. 2 shows the bielastic jersey fabric obtained from Example 1;

FIG. 3 shows the pattern of interlock fabric in which the front overlapof the front and back stitches is shown: the latter are represented bythinner lines solely to help understanding the figure itself, actuallybeing all of the same length and width;

FIG. 4 shows the pattern of the same interlock fabric in FIG. 1 in whichthe overlap of the front and back stitches is shown in perspective; and

FIG. 5 shows the bielastic interlock fabric obtained from Example 3.

DETAILED DESCRIPTION OF THE INVENTION

The invention thus relates to a bielastic fabric comprising biopolyamideyarn and elastane yarn.

The term “bielastic” means that the fabric is elastic in the warp andweft directions.

The term “biopolyamide” means a polyamide entirely or partly of plantorigin. Preferably, the biomass from which the biopolyamide for thepurposes of the present invention originates is the castor seed,referred to as “Ricinus communis”. The monomers used in thepolymerization process are partly or totally derived from castor oil.

Biopolyamides exhibit high resistance to chemical agents, in particularto hydrocarbons, dimensional stability, relatively low density and goodprocessability.

Preferably, said biopolyamide is biopolyamide 6, biopolyamide 6.6,biopolyamide 6.10, biopolyamide 6.12, biopolyamide 11, biopolyamide 12,or a mixture thereof.

More preferably, said biopolyamide is biopolyamide 6.6.

In embodiments, the biopolyamide yarn has a count of 10-200 dTex,preferably 20-150 dTex.

By “elastane” it is meant a synthetic fiber of polyurethane, also knownas Spandex or Lycra.

At present, polyurethane is typically produced from raw materials. Thereaction takes place in two steps, in the first step a polyol is placedto react with a diisocyanate to form an intermediate referred to asprepolymer, which will later be co-linked with amines or glycols. Thepolyol is characterized in that it has hydroxyl functional groups (—OH)at both ends and will form the elastic part of the molecule; it may be apolyester or a polyether or a mixture thereof. The diisocyanate,instead, has isocyanate functional groups (—NCO) at its ends and will bethe rigid part of the polyurethane. The isocyanate most used isdiphenylmethane diisocyanate (“MDI”,1-isocyanate-4-[(4-phenylisocyanate)methyl]benzene).

The reaction takes place between —NCO and —OH groups to form the ureabond and since the molar ratio of isocyanate to polyol is 2:1, the finalproduct will be a macrodiisocyanate, that is, the prepolymer will be amacromolecule having —NCO groups at the ends.

The chain extension is obtained by adding bifunctional amines (H₂NR—NH₂)to the prepolymer, which by reacting with the —NCO groups form aurethane bond. The exothermic reaction increases the molecular weight byhundreds of times and the viscosity therewith; in order to keep theproduct manageable, the reaction is conducted in a suitable solvent andsmall amounts of monofunctional amines regulate the final lengththereof. The most common solvents are dimethylformamide (DMF) anddimethylacetamide (DMAc).

A suitable elastane yarn for the purposes of the present invention isthe yarn described in the international patent application WO0181443.

In preferred embodiments, said elastane yarn is the reaction productbetween (A)poly(tetramethylene-ether-co-2methyltetramethylene-ether)glycol, (B) amixture of 1-isocyanate-4-[(4′-isocyanatephenyl)methyl]benzene(abbreviated “4,4′-MDI”) and 23-55 mol % of1-isocyanate-2-[(4′-isocyanatephenyl)methyl]benzene (abbreviated“2,4′-MDI”) over the total diisocyanate, and (C) at least one chainextender.

More preferably, said elastane yarn is the reaction product between (A)poly(tetramethylene-ether-co-2methyltetramethylene-ether)glycol, (B) amixture of 1-isocyanate-4-[(4′-isocyanatephenyl)methyl]benzene and 28-55mol % of 1-isocyanate-2-[(4′-isocyanatephenyl)methyl]benzene over thetotal diisocyanate, and (C) at least one chain extender.

Preferably, the chain extender is ethylenediamine, 1,4-butanediamine,1,6-hexanediamine, 1,2-propanediamine, 1,3-propanediamine,2-methyl-1,5-pentane-diamine, 1,4-cyclohexanediamine,1,3-cyclohexanediamine, 1,3-diaminopentane, or a mixture thereof.

In preferred embodiments, the chain extender is ethylenediamine.

The elastane yarn is preferably obtained by dry spinning.

Preferably, the bielastic fabric comprises at least 60% of biopolyamideyarn, more preferably at least 70% of biopolyamide yarn.

Preferably, the bielastic fabric comprises at least 5% of elastane yarn,more preferably at least 15% of elastane yarn.

In embodiments, the elastane yarn has a count of 10-200 dTex, preferably15-100 dTex. Alternatively, commercially available elastane yarns may beused, such as the Easy Set LYCRA® yarns marketed by Invista.

Preferably, the bielastic fabric has a basis weight of 50-270 g/sqm(grams/square meter). The basis weight is the weight of a fabric perunit area, expressed in grams per square meter, and is an indication ofthe total amount of fiber in the fabric. Typically, reference is made toa “nominal basis weight” rounded for practical reasons to tens of grams,therefore different from the actual basis weight, which corresponds tothe actual weight per unit area. For the purposes of the presentinvention, the basis weight indicated is a nominal basis weight, whichcorresponds to the actual basis weight ±5 g/sqm. The measurement of thebasis weight is obtained by taking a fabric round having a diameter of11 cm and weighed with a precision balance.

In some embodiments, the bielastic fabric comprises at least 60% ofbiopolyamide yarn and at least 5% of elastane yarn.

Preferably, the bielastic fabric comprises at least 70% of biopolyamideyarn and at least 15% of elastane yarn.

More preferably, the bielastic fabric comprises 75-90% of biopolyamideyarn and 10-25% of elastane yarn.

Preferably, the bielastic fabric has jersey stitch or interlock stitch.

“Jersey” is a fabric made of stocking stitch; the name refers to most ofthe products of the knitwear industry. Produced with knitting machines,it is elastic both in length and in width and if made in warp, it hasladder-proof properties. An example of jersey fabric pattern is shown inFIG. 1.

“Interlock” is a crossed knitted fabric; it is a variant of jersey buteasier to cut; it is one of the fundamental weaving of weft knitting,made on double knit machines, i.e. with two series of needles working inopposite positions. The cylinder needles are coincident with the dialneedles, so they cannot stitch together; so, one yarn is worked by theodd needles of the cylinder needles and the even ones by the dialneedles, thus forming a first row of rib stitch. The subsequent yarn isworked by the needles, which have not worked the first one: a second ribrow is thus obtained, “crossed” with the first one. This results in athickness and volume similar to those of the rib stitch but with a muchmore reduced extensibility. An example of interlock fabric pattern isshown in FIGS. 3 and 4.

In some embodiments, the bielastic fabric has a basis weight of 100-250g/sqm.

Preferably, the bielastic fabric has a basis weight of 180-210 g/sqm,more preferably 190-200 g/sqm.

Preferably, the bielastic fabric has a basis weight of 100-140 g/sqm,more preferably 110-130 g/sqm.

Preferably, the bielastic fabric has a basis weight of 160-200 g/sqm,more preferably 170-190 g/sqm.

In some embodiments, the bielastic fabric has 40-200% of elasticity inthe weft.

Preferably, the bielastic fabric has 45-90% of elasticity in the weft,more preferably 50-80%.

Preferably, the bielastic fabric has 120-200% of elasticity in the weft,more preferably 140-180%.

Preferably, the bielastic fabric has 110-190% of elasticity in the weft,more preferably 130-180%.

In some embodiments, the bielastic fabric has 30-200% of elasticity inthe warp.

Preferably, the bielastic fabric has 35-80% of elasticity in the warp,more preferably 45-70%.

Preferably, the bielastic fabric has 120-200% of elasticity in the warp,more preferably 140-180%.

Preferably, the bielastic fabric has 50-100% of elasticity in the warp,more preferably 60-90%.

More preferably, the bielastic fabric has a basis weight of 100-250g/sqm, 40-200% of elasticity in the weft and 30-200% of elasticity inthe warp.

For the purposes of the present invention, the elasticity is measured bytaking 10×5 cm² strips of fabric and placing them in a dynamometer (e.g.dynamometer Zwick/Roell Z0,5). By “elasticity in the weft” it is meantthe measure of the elasticity taken in the weft direction, while“elasticity in the warp” means the measure of the elasticity taken inthe warp direction.

In some embodiments, the bielastic fabric comprises 75-90% ofbiopolyamide yarn and 10-25% of elastane yarn, and has jersey stitch, abasis weight of 180-210 g/sqm, 45-90% of elasticity in the weft and35-80% of elasticity in the warp. Preferably, the bielastic fabriccomprises 80-90% of biopolyamide yarn and 10-20% of elastane yarn, andhas jersey stitch, a basis weight of 190-200 g/sqm, 50-80% of elasticityin the weft and 45-70% of elasticity in the warp.

In other embodiments, the bielastic fabric comprises 75-90% ofbiopolyamide yarn and 10-25% of elastane yarn, and has jersey stitch, abasis weight of 100-140 g/sqm, 120-200% of elasticity in the weft and120-200% of elasticity in the warp. Preferably, the bielastic fabriccomprises 70-80% of biopolyamide yarn and 20-30% of elastane yarn, andhas jersey stitch, a basis weight of 110-130 g/sqm, 140-180% ofelasticity in the weft and 140-180% of elasticity in the warp.

In further embodiments, the bielastic fabric comprises 75-90% ofbiopolyamide yarn and 10-25% of elastane yarn, and has interlock stitch,a basis weight of 160-200 g/sqm, 110-190% of elasticity in the weft and50-100% of elasticity in the warp. Preferably, the bielastic fabriccomprises 70-80% of biopolyamide yarn and 20-30% of elastane yarn, andhas interlock stitch, a basis weight of 170-190 g/sqm, 130-180% ofelasticity in the weft and 60-90% of elasticity in the warp.

Optionally, the bielastic fabric may further comprise at least one yarnof natural fiber selected from wool, cotton, silk, and flax.

Optionally, the bielastic fabric may further comprise at least one yarnof synthetic fiber selected from polyester, polyamide, acetate, acrylic,rayon, and polyolefin, such as polyethylene or polypropylene.

In some embodiments, the bielastic fabric consists essentially ofbiopolyamide yarn and elastane yarn. The expression “essentiallyconsists of indicates that the fabric may further comprise other typesof yarns which, however, do not alter the technical features of thefinal bielastic fabric.

In further embodiments, the bielastic fabric consists of biopolyamideyarn and elastane yarn.

It is to be understood that all aspects identified as preferred andadvantageous for the bielastic fabric comprising biopolyamide yarn andelastane yarn are to be considered similarly preferred and advantageousalso for the bielastic fabric essentially consisting of biopolyamideyarn and elastane yarn, and for the bioelastic fabric consisting ofbiopolyamide yarn and elastane yarn.

In another aspect, the present invention relates to a manufacturingprocess of the bielastic fabric as described above, said processcomprising the steps of:

-   -   a) stitching biopolyamide yarn and elastane yarn to obtain a        fabric,    -   b) heat-setting said fabric at a temperature not higher than        160° C. over a time period not higher than 100 seconds; and,        optionally,    -   c) dyeing the fabric thus heat-set.

In step a) of the process, a fabric is obtained according to proceduresknown in the field. Preferably, the fabric is obtained by circularknitting with stitching of the two yarns. More preferably, the fabrichas jersey stitch or interlock stitch.

For the purposes of the present invention, the knitting looms areselected on the basis of the gauge of the stitches they produce;preferably, gauge E (expressed as “number of needles per English inch”)ranges from E20 to E50.

In particular, the jersey fabric is obtained with a single knit machine,while the interlock fabric is obtained with a double knit machine.

In step b) of the process, the step of heat-setting of the fabricobtained in step a) is performed.

Heat-setting is a thermal treatment for setting the fibers, impartingdimensional stability to the fabric and constancy of mass per unit areaof the finished fabric.

The thermal treatment may be carried out with various heat sources:

-   -   warm air, in a tentering machine,    -   steam under pressure, in vaporizer,    -   warm water, in HT equipment.

For standard polyamide fabrics, the typical temperatures at whichheat-setting is carried out are 190-195° C.

The biopolyamides allow the heat-setting temperature to bet lowered downto about 165° C.

For standard elastic material fabrics, the typical temperatures at whichheat-setting is carried out are 190-195° C.

It has been surprisingly found that by combining biopolyamide yarn andelastane yarn as described above, it is possible to obtain a heat-setfabric having excellent elastic properties and high dimensionalstability by carrying out the heat-setting step b) at a temperature nothigher than 160° C. This allows a clear advantage in terms of energyconsumption and production efficiency, because the processing time isreduced, all without impairing the technical features of the fabric,such as softness to the touch and bioelasticity, while preserving theoriginal and brilliant colors.

This result is even more surprising when considering that, for the EasySet LYCRA® yarns marketed by Invista, the temperature indicated by themanufacturer for heat setting is 170-175° C.

Therefore, the combination of yarns of the invention goes beyond thealready substantial advantages of the single yarns as compared totraditional yarns considered individually.

Preferably, the heat-setting step b) is carried out over a time periodof 30-70 seconds, more preferably 40-45 seconds.

Preferably, the heat-setting step b) is carried out at a temperature of100-160° C., more preferably of 120-160° C.

Optionally, the process also comprises a step c) of dyeing the heat-setfabric.

Said step may be carried out according to techniques known in the field,however, dyeing is preferably carried out in overflow machines atatmospheric pressure. In this type of machines, the fabric moves atvariable speeds within the bath which consists of water, auxiliaryproducts and dyes. The maximum temperature achievable is lower than 100°C.

In preferred embodiments, the dyeing step c) comprises the followingsubsteps:

-   -   i) scouring at 80-100° C. for 10-20 minutes, preferably at        90° C. for 15 minutes,    -   ii) neutralizing the scouring at 50-70° C. for 5-20 minutes,        preferably at 60° C. for 10 minutes,    -   iii) dyeing, with dye dosage for 15-30 minutes at 90-110° C.        with permanence for 20-40 minutes, preferably for 24 minutes at        98° C. with permanence for 30 minutes,    -   iv) stripping at 30-50° C. for 5-20 minutes, preferably at        40° C. for 10 minutes,    -   v) treating with a fixer at 50-90° C. for 10-30 minutes,        preferably at 70° C. for 20 minutes, and    -   vi) final cold washing.

After this step, the dyed fabric is discharged from the machines andopened, using a specific machinery.

Thereafter, the fabric is dried. Preferably, drying is carried out in atentering machine at a speed of about 20 meters per minute at atemperature of 90° C.

In another aspect, the present invention relates to a bielastic fabricobtainable by the process described above, said bielastic fabriccomprising biopolyamide yarn and elastane yarn.

The fabric thus obtained is very soft, comfortable and technical. It istherefore especially suitable for sea garments, such as swimwear,underwear and sportswear. In a further aspect, therefore, the presentinvention also relates to a clothing item or a furniture item, at leastpartially made of the bielastic fabric of the invention.

By “clothing item” it is meant any article of clothing for men, women orchildren, such as shirt, pant, skirt, jacket, dress, shirt, blouse,sweater, as well as accessories such as handbags, briefcases, wallets,purses, key cases, cases for phones and tablets. In particular, it meansclothing items suitable as sea garments, such as swimwear, underwear andsportswear.

“Furniture item” is meant to include any home linen article, such asbedspreads, curtains, tablecloths and linen for pillows, benches,armchairs, sofas, chairs, beds and ottomans.

It is to be understood that all aspects identified as preferred andadvantageous for the bioelastic fabric should be deemed as similarlypreferred and advantageous also for the manufacturing process and thebioelastic fabric obtained thereby, as well as for the clothing item orfurniture item.

All the combinations of preferred aspects and embodiments of thebioelastic fabric, of the preparing process and of the bioelastic fabricobtained thereby, as well as of the clothing item or furniture item setforth above are further understood as also described. The following arenon-limiting working examples of the present invention.

EXAMPLES Example 1

A Jersey fabric was produced, having basis weight 195 g/sqm andcomprising 83% of biopolyamide yarn (count 88 dTex) and 17% of elastaneyarn (count 44 dTex), by knitting a biopolyamide yarn 6.6 (marketed asFulgar Bio® by Fulgar SpA) and an elastane yarn (marketed as Easy SetLYCRA® by Invista) with circular knitting in a single knit machine(gauge E=E28).

The Jersey fabric thus obtained was subjected to heat-setting in atentering machine at a temperature of 160° C. over a time period of40-45 seconds.

Thereafter, the dyeing step was carried out; the fabric was loaded inoverflow machines and followed the following dyeing cycle:

-   -   scouring at 90° C. for 15 minutes,    -   neutralizing of the scouring at 60° C. for 10 minutes,    -   dyeing, dye dosage for 24 minutes at 98° C. with permanence for        30 minutes, stripping at 40° C. for 10 minutes,    -   treating with a fixer at 70° C. for 20 minutes, and final cold        washing.

After this step, the dyed fabric is discharged from the machines andopened, using a specific machinery.

Thereafter, the fabric is dried in a tentering machine at a speed ofabout 20 meters per minute at a temperature of 90° C.

The bielastic fabric thus obtained is shown in FIG. 2 and has a basisweight of 195 g/sqm, 60% elasticity in the weft and 50% elasticity inthe warp. The measurement of the basis weight was obtained by taking afabric round having a diameter of 11 cm and weighing with a precisionbalance. Instead, the elasticity was measured by taking 12 cm longfabric strips and placing them in a dynamometer Zwick/Roell Z0,5.

Example 2

A Jersey fabric was produced, having basis weight 115 g/sqm andcomprising 76% of biopolyamide yarn (count 28 dTex) and 24% of elastaneyarn (count 22 dTex), by knitting a biopolyamide yarn 6.6 (marketed asFulgar Bio® by Fulgar SpA) and an elastane yarn (marketed as Easy SetLYCRA® by Invista) with circular knitting in a single knit machine(gauge E=E44).

The Jersey fabric thus obtained was subjected to heat-setting in atentering machine at a temperature of 160° C. over a time period of40-45 seconds.

Thereafter, the dyeing step was carried out; the fabric was loaded inoverflow machines and followed the following dyeing cycle:

-   -   scouring at 90° C. for 15 minutes,    -   neutralizing of the scouring at 60° C. for 10 minutes,    -   dyeing, dye dosage for 24 minutes at 98° C. with permanence for        30 minutes,    -   stripping at 40° C. for 10 minutes,    -   treating with a fixer at 70° C. for 20 minutes, and    -   final cold washing.

After this step, the dyed fabric is discharged from the machines andopened, using a specific machinery.

Thereafter, the fabric is dried in a tentering machine at a speed ofabout 20 meters per minute at a temperature of 90° C.

The bielastic fabric thus obtained has a basis weight of 115 g/sqm, 160%elasticity in the weft and 160% elasticity in the warp. The measurementof the basis weight was obtained by taking a fabric round having adiameter of 11 cm and weighing with a precision balance. Instead, theelasticity was measured by taking 12 cm long fabric strips and placingthem in a dynamometer Zwick/Roell Z0,5.

Example 3

An Interlock fabric was produced, having basis weight 175 g/sqm andcomprising 77% of biopolyamide yarn (count 28 dTex) and 23% of elastaneyarn (count 22 dTex), by knitting a biopolyamide yarn 6.6 (marketed asFulgar Bio® by Fulgar SpA) and an elastane yarn (marketed as Easy SetLYCRA® by Invista) with circular knitting in a double knit machine(gauge E=E40).

The Interlock fabric thus obtained was subjected to heat-setting in atentering machine at a temperature of 160° C. over a time period of40-45 seconds.

Thereafter, the dyeing step was carried out; the fabric was loaded inoverflow machines and followed the following dyeing cycle:

-   -   scouring at 90° C. for 15 minutes,    -   neutralizing of the scouring at 60° C. for 10 minutes,    -   dyeing, dye dosage for 24 minutes at 98° C. with permanence for        30 minutes,    -   stripping at 40° C. for 10 minutes,    -   treating with a fixer at 70° C. for 20 minutes, and    -   final cold washing.

After this step, the dyed fabric is discharged from the machines andopened, using a specific machinery.

Thereafter, the fabric is dried in a tentering machine at a speed ofabout 20 meters per minute at a temperature of 90° C.

The bielastic fabric thus obtained is shown in FIG. 5 and has a basisweight of 175 g/sqm, 150% elasticity in the weft and 70% elasticity inthe warp. The measurement of the basis weight was obtained by taking afabric round having a diameter of 11 cm and weighing with a precisionbalance. Instead, the elasticity was measured by taking 12 cm longfabric strips and placing them in a dynamometer Zwick/Roell Z0,5.

Example 4

A Jersey fabric was produced, having basis weight 195 g/sqm andcomprising 83% of biopolyamide yarn (count 88 dTex) and 17% of elastaneyarn (count 44 dTex), by knitting a biopolyamide yarn 6.6 (marketed asFulgar Bio® by Fulgar SpA) and an elastane yarn (marketed as Easy SetLYCRA® by Invista) with circular knitting in a double knit machine(gauge E=E28).

The Jersey fabric thus obtained was subjected to heat-setting in atentering machine at a temperature of 150° C. over a time period of50-55 seconds.

Thereafter, the dyeing step was carried out; the fabric was loaded inoverflow machines and followed the following dyeing cycle:

-   -   scouring at 90° C. for 15 minutes,    -   neutralizing of the scouring at 60° C. for 10 minutes,    -   dyeing, dye dosage for 24 minutes at 98° C. with permanence for        30 minutes,    -   stripping at 40° C. for 10 minutes,    -   treating with a fixer at 70° C. for 20 minutes, and    -   final cold washing.

After this step, the dyed fabric is discharged from the machines andopened, using a specific machinery.

Thereafter, the fabric is dried in a tentering machine at a speed ofabout 20 meters per minute at a temperature of 90° C.

The bielastic fabric thus obtained has a basis weight of 195 g/sqm, 60%elasticity in the weft and 50% elasticity in the warp. The measurementof the basis weight was obtained by taking a fabric round having adiameter of 11 cm and weighing with a precision balance. Instead, theelasticity was measured by taking 12 cm long fabric strips and placingthem in a dynamometer Zwick/Roell Z0,5.

1. A bielastic fabric comprising biopolyamide yarn and elastane yarn. 2.The bielastic fabric of claim 1, having a basis weight of 50-270 g/sqm.3. The bielastic fabric of claim 1, wherein said biopolyamide yarn has acount of 10-200 dTex.
 4. The bielastic fabric of claim 1, wherein saidelastane yarn has a count of 10-200 dTex.
 5. The bielastic fabric ofclaim 1, comprising at least 60% of biopolyamide yarn and at least 5% ofelastane yarn.
 6. The bielastic fabric of claim 1, having jersey stitchor interlock stitch.
 7. The bielastic fabric according to claim 1,having a basis weight of 100-250 g/sqm, 40-200% of elasticity in theweft and 30-200% of elasticity in the warp.
 8. The bielastic fabric ofclaim 7, comprising 75-90% of biopolyamide yarn and 10-25% of elastaneyarn, and having jersey stitch, a basis weight of 180-210 g/sqm, 45-90%of elasticity in the weft and 35-80% of elasticity in the warp, orcomprising 75-90% of biopolyamide yarn and 10-25% of elastane yarn, andhaving jersey stitch, a basis weight of 100-140 g/sqm, 120-200% ofelasticity in the weft and 120-200% of elasticity in the warp, orcomprising 75-90% of biopolyamide yarn and 10-25% of elastane yarn, andhaving interlock stitch, a basis weight of 160-200 g/sqm, 110-190% ofelasticity in the weft and 50-100% of elasticity in the warp.
 9. Thebielastic fabric of claim 8, comprising 80-90% of biopolyamide yarn and10-20% of elastane yarn, and having jersey stitch, a basis weight of190-200 g/sqm, 50-80% of elasticity in the weft and 45-70% of elasticityin the warp, or comprising 70-80% of biopolyamide yarn and 20-30% ofelastane yarn, and having jersey stitch, a basis weight of 110-130g/sqm, 140-180% of elasticity in the weft and 140-180% of elasticity inthe warp, or comprising 70-80% of biopolyamide yarn and 20-30% ofelastane yarn, and having interlock stitch, a basis weight of 170-190g/sqm, 130-180% of elasticity in the weft and 60-90% of elasticity inthe warp.
 10. A process of manufacturing the bioelastic fabric of claim1, comprising the steps of: a) stitching biopolyamide yarn and elastaneyarn to obtain a fabric, b) heat-setting said fabric at a temperaturenot higher than 160° C. over a time period not higher than 100 seconds;and, optionally, c) dyeing the fabric thus heat-set.
 11. The process ofclaim 10, wherein the heat-setting step b) is carried out over a timeperiod of 30-70 seconds.
 12. The process of claim 10, wherein theheat-setting step b) is carried out at a temperature of 100-160° C. 13.The process of claim 10, wherein the dyeing step c) comprises thefollowing substeps: i) scouring at 80-100° C. for 10-20 minutes, ii)neutralizing of the scouring at 50-70° C. for 5-20 minutes, preferablyat 60° C. for 10 minutes, iii) dyeing, with dye dosage for 15-30 minutesat 90-110° C. with permanence for 20-40 minutes, preferably for 24minutes at 98° C. with permanence for 30 minutes, iv) stripping at30-50° C. for 5-20 minutes, preferably at 40° C. for 10 minutes, v)treating with a fixer at 50-90° C. for 10-30 minutes, preferably at 70°C. for 20 minutes, and vi) final cold washing.
 14. A bielastic fabricobtainable by the process of claim 10, comprising biopolyamide yarn andelastane yarn.
 15. A clothing or furniture item, at least partially madeof the bielastic fabric of claim 1 or with the fabric of claim
 14. 16. Aprocess of manufacturing a bielastic fabric comprising biopolyamide yarnand elastane yarn, said process comprising the steps of: a) stitchingbiopolyamide yarn and elastane yarn to obtain a fabric, b) heat-settingsaid fabric at a temperature not higher than 160° C. over a time periodnot higher than 100 seconds; and, optionally, c) dyeing the fabric thusheat-set.
 17. The process of claim 16, wherein the heat-setting step b)is carried out over a time period of 30-70 seconds.
 18. The process ofclaim 16, wherein the heat-setting step b) is carried out at atemperature of 100-160° C.
 19. The process of claim 16, wherein thedyeing step c) comprises the following substeps: i) scouring at 80-100°C. for 10-20 minutes, ii) neutralizing of the scouring at 50-70° C. for5-20 minutes, iii) dyeing, with dye dosage for 15-30 minutes at 90-110°C. with permanence for 20-40 minutes, iv) stripping at 30-50° C. for5-20 minutes, v) treating with a fixer at 50-90° C. for 10-30 minutes,and vi) final cold washing.
 20. A heat-set bielastic fabric obtainableby the process of claim 16, comprising biopolyamide yarn and elastaneyarn, said fabric having a basis weight 10 of 100-250 g/sqm, 40-200% ofelasticity in the weft and 30-200% of elasticity in the warp.